Re: [PATCH v3 5/5] mm: add tracepoints for zone lock

[Dmitry Ilvokhin <d@ilvokhin.com>]

On Thu, Feb 26, 2026 at 01:31:48PM -0800, Shakeel Butt wrote:
> On Thu, Feb 26, 2026 at 01:25:01PM -0800, Andrew Morton wrote:
> > On Thu, 26 Feb 2026 11:14:52 -0800 Shakeel Butt <shakeel.butt@linux.dev> wrote:
> > 
> > > On Thu, Feb 26, 2026 at 06:26:22PM +0000, Dmitry Ilvokhin wrote:
> > > > Add tracepoint instrumentation to zone lock acquire/release operations
> > > > via the previously introduced wrappers.
> > > > 
> > > > The implementation follows the mmap_lock tracepoint pattern: a
> > > > lightweight inline helper checks whether the tracepoint is enabled and
> > > > calls into an out-of-line helper when tracing is active. When
> > > > CONFIG_TRACING is disabled, helpers compile to empty inline stubs.
> > > > 
> > > > The fast path is unaffected when tracing is disabled.
> > > > 
> > > > Signed-off-by: Dmitry Ilvokhin <d@ilvokhin.com>
> > > 
> > > ...
> > >
> > > > +void __zone_lock_do_trace_start_locking(struct zone *zone)
> > > > +{
> > > > +	trace_zone_lock_start_locking(zone);
> > > > +}
> > > > +EXPORT_SYMBOL(__zone_lock_do_trace_start_locking);
> > > 
> > > No reason to not have these as EXPORT_SYMBOL_GPL (& below)
> > 
> > Do we need the exports at all?
> 
> Very good point and we don't. I think this might just be copying the mmap_lock
> tracepoint wrappers which might need the exports as some drivers might be taking
> the mmap_lock.
> 
> Dmitry, please confirm (test) and let us know.

This is a good catch, thank you. I don't think we need EXPORT_SYMBOL()
here. Just verified it locally. I'll remove it in v4.